1. Technical Field
The present invention relates to a manufacturing method for a gas cell, a manufacturing method for a magnetic field measurement apparatus, and a gas cell.
2. Related Art
There is an optical pumping magnetic field measurement apparatus which irradiates a gas cell in which an alkali metal gas is enclosed with linearly polarized light, and measures a magnetic field according to a rotation angle of a polarization plane (for example, refer to JP-A-2013-7720). JP-A-2013-7720 discloses a configuration of a gas cell and a manufacturing method therefor in which an alkali metal substance is accommodated in a cavity of a cell whose inner wall is coated with paraffin, the cavity is sealed, and an alkali metal gas is generated through a thermal reaction or the like so as to fill the cell inside. According to the disclosure of JP-A-2013-7720, a coating material is disposed in a cavity formed in a substrate, and the cavity is sealed by disposing another substrate on the substrate. The coating material is vaporized by heating the entire cell, and is then cooled so that a coating material layer is formed on the inner wall of the cavity.
The coating material layer has a function of preventing or reducing a change in a behavior (for example, spin) when alkali metal atoms directly collide with the inner wall of the cell. Paraffin which is appropriately used as a coating material is generally a soft solid (waxy) at the room temperature, and is thus hard to handle when an amount thereof is finely adjusted or the paraffin is disposed inside the cell. Thus, there is concern that an amount of disposed paraffin may vary in a disposing step, or the number of steps may increase, but JP-A-2013-7720 does not disclose a method of handling or disposing a coating material.
If an amount of the coating material disposed inside the cell varies, a coating material film formed on the inner wall of the cell may not have a desired film thickness, and thicknesses of coating material films may be different from each other between individuals. Thus, there is a problem in that quality (sensitivity, measurement accuracy, or the like) of a manufactured gas cell deteriorates, or differences between qualities of individuals occur.